There is a continuing interest in providing consumers with personal cleansing compositions which not only cleanse the skin, but which also provide additional skin care benefits. For example, it would be highly desirable to provide products which both thoroughly cleanse the skin and which also deposit various active ingredients upon the skin surface during the cleansing process. These dual goals of cleansing the skin and depositing an active are difficult to achieve from a single product, because the surfactant ingredients typically found in a skin cleansing product tend to inhibit the deposition of actives from the product and also tend to remove the actives which have deposited. Therefore, the need exists to develop compositions which effectively achieve both of these goals of cleansing and deposition.
A significant segment of the population suffers from acne.
These individuals have special skin cleansing needs. Acne sufferers need to keep their skin clean to remove dirt, oils, bacteria, and other foreign materials. Acne sufferers also need to treat their skin with various medicaments to both ameliorate exisiting acne lesions and to prevent future acne lesions. Even though cleansing products which contain various active ingredients are known and are targeted to acne sufferers, many of these cleansing products do not effectively deposit therapeutic levels of the active ingredients upon the skin. Therefore, acne sufferers need to use two separate products, namely a cleansing product followed by an anti-acne medicament, to obtain effective anti-acne protection.
Not only acne sufferers have the unmet need of finding products which both cleanse and treat the skin. For example, a significant segment of the population is concerned with skin aging effects, i.e. wrinkling, sagging, age spots, and other age-related skin changes. These individuals also have special skin cleansing needs. These individuals need to keep their skin clean and also need to treat their skin to reduce the aging effects which have already occurred and to prevent or diminish future aging effects from occurring. Furthermore, these individuals also have the need to moisturize their skin. As with acne sufferers, there is again a lack of products which both cleanse and treat the skin, thus necessitaing the use of separate cleansing and treatment products.
A wide variety of active ingredients are currently known for treating various skin conditions. Representative of some of these active ingredients is salicylic acid. Salicylic acid is a well known keratoylic agent which is believed to help remove keratin plugs and to aid the skin's exfoliation process. Salicylic acid is described further in C. Huber et al., Arch. Derm. Res. 257, pp. 293-297, 1977). Salicylic acid is known for its anti-acne benefits and is available in numerous over-the-counter products. See C. Huber et al., Arch. Derm. Res. 257, pp. 293-297, 1977. Salicylic acid is also known for its anti-skin aging benefits. See PCT Patent Application No. 9310755, to Blank et al., published Jun. 10, 1993 and PCT Application No. 9310756, to Blank, published Jun. 10, 1993. However, it is difficult to deliver effective levels of salicylic acid to the skin from conventionl skin cleansing products. This challenge is especially difficult in light of FDA regulations which limit the level of salicylic acid in skin care products to only 2%. See, "Topical Acne Drug Products For Over The Counter Human Use Final Monograph", 21 CFR 333, Aug. 16, 1991. Thus the need exists for developing products which thoroughly cleanse the skin and which also deliver therapeutically effective levels of salicylic acid to the skin within the FDA formulation constraints.
It has been found in the present invention that cleansing compositions in the form of oil-in-water emulsions can be formulated which are useful for both cleansing the skin and depositing effective levels of a wide variety of active ingredients during the cleansing process. It has been found that these emulsions are useful for depositing actives having a solubility parameter from about 7 to about 13. It has also been found that these emulsions are especially useful for depositing salicylic acid.
It is an object of the present invention to provide personal cleansing oil-in-water emulsion compositions which are useful for both cleansing the skin and depositing active ingredients upon the skin surface during the cleansing process.
It is a further object of the present invention to provide compositions which are useful for both cleansing the skin and providing an anti-acne benefit.
It is a further object of the present invention to provide compositions which are useful for both cleansing the skin and providing an anti-skin aging benefit.
It is a further object of the present invention to provide compositions which are useful for both cleansing the skin and for depositing salicylic acid upon the skin surface during the cleansing process.
It is a further object of the present invention to provide methods for cleansing the skin and for depositing active ingredients upon the skin surface.
These and other objects of this invention will become apparent in light of the following disclosure.